Transparency

[Doug Nebert]

All:

I would like to manufacture certain layers as being transparent outside
of the opaque features so they can be overlain on similar maps from 
other servers. I want roads opaque, background transparent. 

Is there a correct way to specify the transparent color bin to use,
through mapfile or other setting?  I am using mapserv with the old
gd that supports GIF format. I understand that the PNG files use a
different method for transparency, but would hope that this is 
defined in a single way via map file. Is it defined at all?

Doug.

-- 
Douglas D. Nebert
Geospatial Data Clearinghouse Coordinator 
FGDC Secretariat	Phone: +1 703 648 4151	Fax: +1 703 648-5755	
Pager Messaging: 	http://clearinghouse3.fgdc.gov/dougmsg.html